1. Field of the Invention
The invention relates to a seating furniture component or the like, especially an upholstered furniture component with a coupled backrest and seat adjustment. It as well covers sittable reclining furniture, for example, an upholstered recliner with height-adjustable back part or a corresponding hospital bed. Particularly, the invention relates to such a furniture component with a support chassis, a backrest adjustably attached to the support chassis, a seat adjustably attached to the support chassis, an adjustment mechanism between the support chassis, backrest and seat which accomplishes synchronous adjustment of the backrest and seat, the backrest executing a superimposed tiltback and lowering motion from the highest upright position, i.e., the sitting position, into the lowest extended position, i.e., the reclining position, relative to the support chassis, the seat executing a slight motion from the sitting position to the reclining position, preferably a superimposed sliding and lifting motion, and preferably with a reset spring being provided.
2. Description of Related Art
Variously comfortable and variously complex seating furniture components (armchair, upholstered armchair, easy chair, bus, railroad and aircraft seat, reclining furniture with height adjustable back part), especially upholstered furniture components, in which the backrest adjustment and seat adjustment are coupled are known in the prior art. For example, published International Application WO95/25452 discloses a chair with a reclinable backrest of the type to which the teachings of this invention are applicable and provides a good outline of the generally known prior art.
First of all, in the seating furniture component disclosed in the noted Application WO95/25452 (FIGS. 1 & 2), the backrest forms an angularly-rigid unit with the seat which is attached to a support frame so as to pivot about an axis located under the seat, such that the backrest tilts back and down when leaning backwards into the reclining position, while the back end of the seat swings down and the front end swings up. This is normally done against the force of a reset spring. Here, the angularly-rigid connection of the backrest and seat adjustment is disruptive, and therefore, there is no extended position of the backrest and seat. In addition, it is disruptive that the front edge of the seat is moved considerably upward in the reclining position, this is not especially beneficial for the legs of the user.
An alternate construction of the seating furniture component shown in application WO95/25452 (FIG. 3 & 4) is a relatively common one in which the support chassis is made frame-like. The backrest is pivotally connected to the rear part of the frame-like support chassis a considerable distance above the connection point of the backrest to the rear edge of the seat. The rear edge of the seat is thus supported by means of the backrest on the support chassis. On or near the front edge, the seat is guided in a slide guide which has only a slight upward inclination, so that the front edge of the seat moves forward, but only slightly up in the transition from the sitting position to the reclining position.
In the aforementioned system, a user can move relatively easily and without expending a large amount of force into different positions between the sitting position and reclining position by shifting his body weight. It is generally necessary to use an additional braking means to be able to maintain a certain desired position, or a balancing spring means.
One disadvantage in the seating furniture component results from the pivot connection of the backrest and the seat roughly at the vertex of the angle of the two components. The connection of the two components is structurally simple, but the two components generally carry upholstered supports. The upholstered surfaces of the upholstered supports used by the user are thus somewhat above the seat or in front of the backrest and thus somewhat above or in front of the pivot axis between the backrest and seat. This results in the fact that, in the transition from the sitting position to the reclining position, the upholstered supports move away from one another; this results in a "shirt pullout effect" which the user perceives as very unpleasant.
Another problem which is likewise the result of the aforementioned pivot connection is that a "hole" forms in the pelvis/back area at the angle vertex in the transition from the sitting position into the reclining position. This "hole" is disruptive when it is too large since the pelvis/flank area is then no longer properly supported in the reclining position.
Finally, the attachment of the seat to the front edge must be carefully done so that an overly great blow into the hollows of the knee of the user does not occur in the transition from the sitting position to the reclining position.
Attempts have already been made in the prior art to eliminate the "shirt pulling effect" by providing a connection mechanism between the backrest and the seat, in the area of the rear edge or lower edge, which places the axis of the pivot connection between the backrest and seat roughly where the surfaces of the two upholstered supports abut one another in the sitting position. This is done by flaps which project from the respective frame on the edge side and which are joined to pivot with one another only on their free ends (FIGS. 5 & 6 of WO95/25452).
Analysis of this known seating furniture component has shown that, as before, the "shirt pullout effect" is noticeable when a relatively extended reclining position is desired. In addition, the "hole" in the pelvis/back area is still too large. Finally, the embodiment of the above explained prior art results in major lifting of the front edge of the seat takes place. This may be acceptable for a seat with footrests, but this is not the case for a seating furniture component of the type under consideration which generally has a foldable footrest.